1. Field of the Invention
This invention relates to lens covers or filters for use with headlights of automobiles wherein the filter or lens cover may be removably positioned on the highlights for use only during conditions of rain or fog.
2. Brief Description of the Prior Art
It has been common practice for many years to use a special fog lamp having colored lenses on automobiles for improved visibility in fog and rain. It has been known for many years that visibility under conditions where the light admitted by automobile headlights is diffused and reflected in the atmosphere directly in front of the vehicle, as by fog or rain, can be improved by altering the color of the light and decreasing its intensity somewhat. It has been known for a long time that amber or yellow light is particularly advantageous from the standpoint that it permits greater intensity before reflection and diffusion of light become unduly troublesome than is possible when white light or light of other colors is used.
Modern motor vehicles are provided with sealed beam headlights of a shape and size which has been standardized over a period of years. Most modern vehicles have twin headlights on each side wherein one of the lights is a high-beam and the other a low-beam. Somewhat older vehicles may be provided with sealed beam headlights of standardized size and shape wherein the light has two alternately usuable filaments arranged to provide a low beam of light or a high beam of light according to which filament is used. Both beams of light are of relatively high intensity and the lenses of such headlights and the lenses of twin beam headlights are not colored, since for driving in clear weather the reduced intensity of light caused by coloring the lens results in too great a loss of illumination.
Automobiles are commonly provided with parking lights of very low intensity but these cannot be used in fog and rain since the amount of light provided is too little. To overcome these difficulties, it has been quite common to equip vehicles with auxiliary fog lights having colored lenses. Such lights are expensive and troublesome to install. If fog lights are supported on the front bumper they are subject to being damaged or becoming maladjusted from contact with other surfaces, e.g. bumpers of other cars, a wall of a garage, etc.
The Lightfoot U.S. Pat. No. 1,129,106 discloses the use of a small colored light filter removably positioned over the central portion of an automobile headlight.
Ellis U.S. Pat. No. 1,364,189 discloses flood lights having a lens consisting of a lamination of clear glass and colored glass held together removably by a detachable rim. Obviously, such a flood light could be used as automobile headlight.
Cyr U.S. Pat. No. 2,544,378 discloses a removable fog filter for automobile headlights. The filter is secured by rubber suction cups to the headlight with a substantial space between the headlight and the filter.
Kosmatka U.S. Pat. No. 4,006,377 discloses the application of colored lens covers or filters to sealed beam automobile headlights by use of a heat-shrinkable plastic ring which fastens and seals the filter to the headlight. This arrangement is for affixing the filter or lens cover permanently at the time of original manufacture.